February 4, 2020

The Bilingual Brain — the power of linguistics and learning

Financial Times

FEBRUARY 4, 2020

Albert Costa explores how bilingualism remains freighted with prejudice

A child from Bangladesh sits next to an Irish child at Kingsmead primary school in Hackney © Corbis via Getty

Ever since I turned up at school, in an east London suburb in the 1990s, knowing little to no English, I have never lost the feeling of playing catch-up. In the playground, I picked up a salty, slangy dialect known as “Estuary English”, which meant I mispronounced my own name. Eventually a teacher decided to correct me. Beckoning me to the front, she asked me to say my name to the class. Relieved I knew the answer for a change, I replied: “Tanjyooow”. But somehow I had got it wrong and, by way of correction, I had to repeat the rhyme “Tanjil like Jack and Jill”, until every “L” was sounded flawlessly.

Besides that humiliation, the teachers also forbade us from chattering with our ethnic peers in our mother tongues. These practices probably hastened adjustment to English, but they left enduring anxieties about language. By the time I knew enough English to read Shakespeare, I lingered with recognition over the image, in Richard II, of the repression of language: “within my mouth you have enjailed my tongue/ Doubly portcullised with my teeth and lips”.

These neuroses about language obviously relate to, and may even originate in, the brain, which controls language and, arguably, consciousness. The idea of The Bilingual Brain — Spanish neuropsychologist Albert Costa’s new book — is therefore tantalising to those of us who are bilinguals. Far from being a niche experience, this category actually encompasses just over half the world’s population, according to linguistic demographers.

The statistical prevalence of bilingualism overturns old-school linguistics, premised as it was on monolingualism as the norm and bilingualism as the aberration. This was no innocuous academic oversight; negative claims about bilingualism, that it inhibited mental development, circulated widely for decades, from parents to pedagogues.

Bilingualism is a state of being, with each language standing guard, poised for action

Even when I was at school, long after these theories had been debunked, I was removed from the classroom together with children I now realise were autistic or dyslexic, to do degradingly simple tasks with the special needs teacher. The aim was to keep bilinguals from falling behind even in, for example, arithmetic because bilingualism was considered a blanket learning disability.

The Bilingual Brain will hopefully be a popular rejoinder to these persistent misconceptions. As Costa informs us, no evidence of a “cognitive bilingual disadvantage” exists. But neither does Costa swing too far the other way now the debate has shifted to a hypothetical advantage. The neurological evidence, in Costa’s telling, shows bilingualism has no “dramatic effects on linguistic capacity or any other cognitive domain”.

Bilingualism is not difficult or confusing. We picture sophisticated adults who have studied or travelled widely. In fact, illiterate hunter-gatherers are more multilingual than college-educated westerners. In remote Australia, the average aboriginal will speak at least three or four of 145 indigenous languages, while white Australians, though better educated, mostly speak just one.

Bilingualism is so straightforward babies are capable of it before they can even speak; Costa shows how newborns instinctively differentiate their native languages from non-native ones.

His focus on those who have been bilingual from a young age stems from the finding that life-long bilinguals manifest intriguing divergences in how their brains process language, whereas people who become bilingual late in life hardly vary in their brain processes from monolinguals.

Bilingualism is a permanent state of being, with each language standing guard, poised for action. This means the bilingual brain exercises immense control when speaking, to stop words coming out in the wrong tongue. Costa believes this finesses the brain’s “executive control”, improving concentration and multitasking. At the same time, because bilingual brains sift through more words to get to the right one, their speech reaction times are fractionally slower.

The concept of neuroplasticity — the brain’s changing form — is crucial to the bilingual brain. Its youthful malleability makes childhood the critical period in which the brain is “sculpted” by its linguistic environment. This is why children learn languages so easily, before their brains are set, if not in stone, in grey matter. Neuroimaging highlights the bilingual brain’s more intense use of “neural networks”, but real-world consequences of this, if any, are unknown.

These kinds of brain scans are so new, and these social experiments so complex (is bilingualism the crucial factor, or immigration or education?), that Costa’s claims come highly qualified. A rare, unmitigated conclusion, however, is that bilingualism is a restorative tonic for the ageing brain. Bilinguals are not immune to dementia, when the brain starts shrinking incurably, yet its symptoms — the slackening of memory and thought — are mysteriously delayed by around four years. Neuroscientists have recently begun clarifying more philosophical questions about consciousness and thought. Many researchers believe the latter to be coloured by the peculiarities of one’s native language. But what if we have two native languages? No one, including Costa, has properly explored this, and neuroscience might have helpfully intervened in the interminable feuds of philosophers of language.

For all its cerebral insights and neuroimaging colour plates, The Bilingual Brain lacks feeling for the bilingual experience. That, ultimately, resides not in abstract blotches on an MRI scan, but in the wider world in which we use our languages — my Bengali, heartfelt and speculative; my English, lucid and empirical — to interpret and interact with our surroundings so much more richly.

“The limits of my language are the limits of my world”, wrote the philosopher Wittgenstein — a dour, pessimistic truth for monolinguals cramped within their lone imaginative lexicon. But for a bilingual, the boundaries are pushed, and the world opened up, by the gift of dual perception.